Question

Now that you know how fast your bacteria grows, you want to determine its metabolic strategy. You grow the bacteria in a liquid media, and do not notice any pigments or coloration of the culture. Interestingly, you grow the bacteria at different temperatures and find that your bacteria grows best at temperatures above 50 degrees celsius. You perform a gram stain on the organism, and you see pink rod-shaped bacteria. You find that your bacteria does not grow in the presence of oxygen, but requires H2 and CO2 present in atmosphere. The growth of your bacteria does not seem to be affected by different sugars in the media, but through some clever sleuthing, you determine your bacteria does require Nittrate (NO3-) in the media to grow. What is the metabolic strategy of this organism?

Answer 1

This organisms could be a denitryfying bacteria that reduces nitrate to molecular nitrogen anaerobically.When oxygen is present in limited amount, some bacteria use nitrate to support the process of respiration.Thus,denitrification always occurs under anaerobic conditions with the use of soluble carbon compounds,(e.g CO2 )and oxidized forms of N (e.g nitrates or nitrites).